Compound eye laser tracking device

Abstract

The Compound Eye Laser Illumination Seeker is a tracking system used to guide items to point at a laser-illuminated target, with the illumination being either pulsed or modulated at either a specific rate or within a range of rates. The device comprises a multiaperture compound receiver optics to collect the signal, a set of light guides to combine the received light into light representing individual angular sectors and redirect it to detectors whose output represents the illumination signal in that quadrant, a spectral filter, an angle filter, the set of detectors, and processing electronics. The output is an electronic signal indicating the angular difference between the pointing direction of the signal and the pointing direction of the tracking device.

The invention claimed is: 
     
       1. A method for tracking an optical signal in the presence of optical noise, comprising
 A tracking system having no moving parts, said tracking system having a lens array for collecting the signal; 
 filtering the signal with a substrate guided holographic relay for selecting specific wavelengths or wavelength ranges, and for limiting the angular field of view of each lens; 
 directing the signal to one or more photodetectors; 
 processing the output of the one or more photodetectors so that a correction signal is produced which describe an angular difference between a pointing direction of the correction signal and a pointing direction of a tracking device, and sending the correction signal to a direction control system for implementation. 
 
     
     
       2. The method of  claim 1  wherein the lens array is mounted to a curved surface. 
     
     
       3. The method of  claim 1  wherein the filtering steps comprises utilizing two holographic optical elements integrated on a flat glass substrate. 
     
     
       4. The method of  claim 1  wherein the step of directing the signal to one or more photodetectors utilizes an optical fiber bundle. 
     
     
       5. The method of  claim 1  wherein the step of directing the signal to one or more photodetectors utilizes a light guide. 
     
     
       6. The method of  claim 5  wherein filtering the signal to limit angular field of view is with the light guide. 
     
     
       7. The method of  claim 1  wherein filtering the signal to select specific wavelengths is with one or more optical bandpass filters. 
     
     
       8. The method of  claim 7  wherein each optical bandpass filter is formed from a combination of a shortpass filter and a longpass filter. 
     
     
       9. The method of  claim 1  wherein the one or more photodetector comprises a single detector whose output indicates the position of a light on the detector. 
     
     
       10. The method of  claim 1  wherein the one or more photodetector comprises a plurality of detectors. 
     
     
       11. The method of  claim 1  further including noise filtering. 
     
     
       12. The method of  claim 1  wherein output of the one or more photodetector is analog. 
     
     
       13. The method of  claim 1  wherein the output of the one or more photodetector is digital. 
     
     
       14. A compound eye laser illumination seeker, comprising multi aperture compound receiver optics having no moving parts, the optics having a lens array, the lens array being aligned with a light guide array, a spectral and angle filter for eliminating extraneous light and sending a signal to a set of detectors; a processor for processing the signal to calculate a correction signal, said spectral and angle filter comprising a holographic optical lens integrated on a flat transparent substrate and a direction control system for receiving the correction signal and implementing the correction signal. 
     
     
       15. The compound eye laser illumination seeker of  claim 14  wherein the set of detectors comprise four photo detectors. 
     
     
       16. The method of  claim 1  wherein the step of filtering the signal with a substrate guided holographic relay utilizes a combined angular and spectral filter.